Infecção de Biomphalaria glabrata com Angiostrongylus costaricensis : desenvolvimento larval e resposta hemocitaria / Infection of Biomphalaria glabrata of Angiostrongylus costaricensis : larval development and hemocyte response

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Biomphalaria glabrata can be experimentally used as an intermediate host of the nematode Angiostrongylus costaricensis, responsible for abdominal angiostrongyliasis. This zoonosis, found in Brazil mainly in the southem states, can accidentally infect man through the ingestion of parasitized mollusks or contaminated water and food containing third-stage larvae, eliminated in the mucous secretion of the mollusks. The objective of this work was to study the development of larval stages and the behavior of hemocytes in the hemolymph of infected B. glabrata. A total of 168 mollusks were infected with 120 LI larvae of A. costaricensis, extracted ftom excrement of albino Swiss mice previously infected via the oral route by esophageal tube with 6 L3 larvae. The A. costaricensis larvae had been recovered from 45 B. glabrata mollusks at 15, 22 and 29 days after exposure to the parasite, by means of the method of Baermann, using molluscan tissues digested with pepsin and hydrochloric acid solution. A larger recovery of A. costaricensis larvae from the mollusk was found at 29 days after infection. For the study of the development of A. costaricensis, 60 infected mollusks were allocated for larval recovery during a period of 30 consecutive days. It was observed that there was a larval stage change, from L1 to L2, at the 13th day after infection and from L2 to L3 on the 18th day after infection.The hemolymph of 45 mollusks, both infected and not infected with A. costaricensis, was collected for verification of the hemocyte response during 4 weeks. The hemocytes were differentiated into hyalinocytes and granulocytes. While in the non infected mollusks the hyalinocytes had predominated, in those infected granulocytes were more evident, mainly between the 18th and the 25th day after infection. The occurence of infection, both via percutaneous and via oral routes, was confirmed. The most parasitized sites were the cephalopodan mass, preferred by the nematodes, folIowed by the intestines, kidneys and lungs. AlI the larvae found were viable and surrounded by reaction of the granulomatous type, independent of their situation

ASSUNTO(S)

angiostrongylus costaricensis angiostrongylus costaricensis biomphalaria glabrata biomphalaria glabrata hemocitos life cycle stages fases do ciclo de vida hemocytes

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